Pen does require less pressure and is often easier for a child who tires quickly at writing tasks (issues with small motor skills, etc.). I am teaching cursive “my way” (the way I was taught, though I’m not sure which “style” it would be). I don’t believe it is necessary to spend a ton on cursive materials for a particular “style”. My own “everyday handwriting” is a mixture of print and cursive, so it’s been good practice for me as well. We will be typing up the majority of our written narrations, so I don’t have a problem if my ds prefers pen for note-taking or anything that is not graded. We will transition to pen for copywork this year, I think.
Ultimately, if your comfortable with your child using pen, and you feel it adds to pride in her work and more careful attention and concentration, start transitioning her. Obviously it is easier to correct mistakes in pencil, so I would stick with pencil in Math.